The micro-lens array is expected to find applications in various fields, such as optical systems of electronic copiers and FAX machines, optical print heads of light-emitting diode (LED) or liquid crystal display (LCD) printers, and in liquid crystal display devices, solid-state image pickup elements, multiple image transmission by optical interconnection, confocal-type laser microscopes, and other applications in the optical communication field, optical disk field, image display field, image transmission/coupling field, optical measurement and optical sensing field, optical processing field, etc. Usually, such micro-lens arrays are required to have a high quality (high resolution) free of stray light.
For the lens array, it is necessary to form plural lenses. As the method for forming a row of plural lenses on a transparent substrate, the following scheme for forming the micro-lens array may be adopted: after a light shielding layer is formed on a transparent substrate, the portions between the light shielding layer are filled up with a lens material (pixel sections) by using an inkjet method, followed by heating to have the lens material in a curved shape for forming the micro-lens array. Unfortunately, for the lens array prepared using this method, it is impossible to obtain excellent optical characteristics.